A wireless device typically operates using a radio transmitter/receiver (“transceiver”) and one or more antennas. Recently, diversity antennas have been applied to wireless devices such as mobile telephones and handheld computers. In general, diversity antennas are based on the concept of a smart array and tend to improve the receiving sensitivity of a wireless device by reducing multi-path interference.
FIG. 1 illustrates a wireless device 100 having a conventional diversity antenna architecture. As shown, the wireless device 100 comprises an external housing 102 and a printed circuit board (PCB) 104. The diversity antenna architecture includes an external antenna 106 and an internal antenna 108 having different polarized radiation patterns to reduce mutual coupling and allow cooperative operation.
Antenna orientation for a given wireless device is an important design consideration and is often limited by strict performance constraints. For example, some antenna placements may be undesirable since they may increase the overall size and shape of the wireless device. In addition, some external antenna placements may expose the antenna to potential damage. Further, some extendable antennas may provide reduced performance, and in some cases may not provide any performance at all, when in a retracted or closed position. Such problems may be further exacerbated for those wireless devices with smaller form factors such as a mobile telephone or handheld computer. Consequently, there may be a need for improvements in antenna design.